Class: Cumulus::AutoScaling::AlarmConfig

Inherits:
Object
  • Object
show all
Defined in:
lib/autoscaling/models/AlarmConfig.rb

Overview

Public: A class that encapsulates data about configuration for an autoscaling Cloudwatch alarm.

The action to be taken is inferred to be activating the policy that contains the alarm. As such, we don’t keep arrays of actions to take when various alarm states are triggered. We just apply the action (activating the policy) to the states contained in the ‘action_states` array. Valid values are “alarm”, “ok”, and “insufficient-data”.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(json = nil) ⇒ AlarmConfig

Public: Constructor

json - a hash containing the JSON configuration for the alarm



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 31

def initialize(json = nil)
  if !json.nil?
    @action_states = json["action-states"]
    @actions_enabled = json["actions-enabled"]
    @comparison = json["comparison"]
    @description = json["description"]
    @dimensions = json["dimensions"]
    @evaluation_periods = json["evaluation-periods"]
    @metric = json["metric"]
    @name = json["name"]
    @namespace = json["namespace"]
    @period = json["period-seconds"]
    @statistic = json["statistic"]
    @threshold = json["threshold"]
    @unit = json["unit"]
  end
end

Instance Attribute Details

#action_states ⇒ Object (readonly)

Returns the value of attribute action_states.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 14

def action_states
  @action_states
end

#actions_enabled ⇒ Object (readonly)

Returns the value of attribute actions_enabled.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 15

def actions_enabled
  @actions_enabled
end

#comparison ⇒ Object (readonly)

Returns the value of attribute comparison.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 16

def comparison
  @comparison
end

#description ⇒ Object (readonly)

Returns the value of attribute description.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 17

def description
  @description
end

#dimensions ⇒ Object (readonly)

Returns the value of attribute dimensions.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 18

def dimensions
  @dimensions
end

#evaluation_periods ⇒ Object (readonly)

Returns the value of attribute evaluation_periods.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 19

def evaluation_periods
  @evaluation_periods
end

#metric ⇒ Object (readonly)

Returns the value of attribute metric.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 20

def metric
  @metric
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 21

def name
  @name
end

#namespace ⇒ Object (readonly)

Returns the value of attribute namespace.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 22

def namespace
  @namespace
end

#period ⇒ Object (readonly)

Returns the value of attribute period.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 23

def period
  @period
end

#statistic ⇒ Object (readonly)

Returns the value of attribute statistic.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 24

def statistic
  @statistic
end

#threshold ⇒ Object (readonly)

Returns the value of attribute threshold.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 25

def threshold
  @threshold
end

#unit ⇒ Object (readonly)

Returns the value of attribute unit.



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 26

def unit
  @unit
end

Instance Method Details

#diff(aws, policy_arn) ⇒ Object

Public: Produce the differences between this local configuration and the configuration in AWS

aws - the alarm in AWS policy_arn - the policy arn is the action this alarm should take

Returns an array of AlarmDiff objects representing the differences



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 102

def diff(aws, policy_arn)
  diffs = []

  if @description != aws.alarm_description
    diffs << AlarmDiff.new(AlarmChange::DESCRIPTION, aws, self)
  end
  if @actions_enabled != aws.actions_enabled
    diffs << AlarmDiff.new(AlarmChange::ENABLED, aws, self)
  end
  if @comparison != aws.comparison_operator
    diffs << AlarmDiff.new(AlarmChange::COMPARISON, aws, self)
  end
  if @evaluation_periods != aws.evaluation_periods
    diffs << AlarmDiff.new(AlarmChange::EVALUATION, aws, self)
  end
  if @metric != aws.metric_name
    diffs << AlarmDiff.new(AlarmChange::METRIC, aws, self)
  end
  if @namespace != aws.namespace
    diffs << AlarmDiff.new(AlarmChange::NAMESPACE, aws, self)
  end
  if @period != aws.period
    diffs << AlarmDiff.new(AlarmChange::PERIOD, aws, self)
  end
  if @statistic != aws.statistic
    diffs << AlarmDiff.new(AlarmChange::STATISTIC, aws, self)
  end
  if @threshold != aws.threshold
    diffs << AlarmDiff.new(AlarmChange::THRESHOLD, aws, self)
  end
  if @unit != aws.unit
    diffs << AlarmDiff.new(AlarmChange::UNIT, aws, self)
  end
  aws_dimensions = Hash[aws.dimensions.map { |d| [d.name, d.value] }]
  if @dimensions != aws_dimensions
    diffs << AlarmDiff.new(AlarmChange::DIMENSIONS, aws, self)
  end

  ["ok", "alarm", "insufficient-data"].each do |state|
    case state
    when "ok"
      actions = aws.ok_actions
      change_type = AlarmChange::OK
    when "alarm"
      actions = aws.alarm_actions
      change_type = AlarmChange::ALARM
    when "insufficient-data"
      actions = aws.insufficient_data_actions
      change_type = AlarmChange::INSUFFICIENT
    end

    if (!@action_states.include?(state) and actions.size != 0) or
      (@action_states.include?(state) and (actions.size != 1 or actions[0] != policy_arn))
      diff = AlarmDiff.new(change_type, aws, self)
      diff.policy_arn = policy_arn
      diffs << diff
    end
  end

  diffs
end

#hash ⇒ Object

Public: Get the configuration as a hash

Returns the hash



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 52

def hash
  {
    "name" => @name,
    "action-states" => @action_states,
    "actions-enabled" => @actions_enabled,
    "comparison" => @comparison,
    "description" => @description,
    "dimensions" => @dimensions,
    "evaluation-periods" => @evaluation_periods,
    "metric" => @metric,
    "namespace" => @namespace,
    "period-seconds" => @period,
    "statistic" => @statistic,
    "threshold" => @threshold,
    "unit" => @unit
  }.reject { |k, v| v.nil? }
end

#populate(policy_arn, resource) ⇒ Object

Public: Populate the AlarmConfig from an existing AWS cloudwatch alarm

policy_arn - the arn of the policy the alarm should be attached to resource - the aws resource to populate from



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# File 'lib/autoscaling/models/AlarmConfig.rb', line 74

def populate(policy_arn, resource)
  action_states = []
  if resource.ok_actions.include?(policy_arn) then action_states << "ok" end
  if resource.alarm_actions.include?(policy_arn) then action_states << "alarm" end
  if resource.insufficient_data_actions.include?(policy_arn) then action_states << "insufficient-data" end

  @action_states = action_states
  @actions_enabled = resource.actions_enabled
  @comparison = resource.comparison_operator
  @description = resource.alarm_description
  @dimensions = Hash[resource.dimensions.map { |d| [d.name, d.value] }]
  @evaluation_periods = resource.evaluation_periods
  @metric = resource.metric_name
  @name = resource.alarm_name
  @namespace = resource.namespace
  @period = resource.period
  @statistic = resource.statistic
  @threshold = resource.threshold
  @unit = resource.unit
end